Sauté the ground beef and chopped onion in a large skillet over a medium heat. Mix the beef to prevent it sticking to the pan, cook until its browned all over. Drain and set aside.

For the main cooking use a slow cooker, Crockpot, or large pot. Place the cooked beef and onion mixture into the pot, add the taco seasoning, tomato sauce, drained kidney beans and drained corn. If using a slow cooker, cover and cook on low setting for 90 minutes. If using a large pot then cover and simmer gently for 30 minutes. Stir the soup occasionally during cooking.

Ladle the the soup into individual bowls and top with tortilla chips, cheese and green onions.